Optimizing Micro-irrigation Pipe Network Operated by Self-Regulated Pressure Using the Shuffled Frog-leaping Algorithm

Abstract

【Background】Micro-irrigation, including drip irrigation, micro-sprinkler irrigation and small-tube discharge irrigation, is a technology using pipe network to convey water to fields and then to root zones via orifice or emitter capillary tubes. Current design of the pipe network relies on empirical experiences and follows traditional references, and it is hence unlikely to be optimal. Developing optimal design method is required to improve efficiency of the micro-irrigation system and reduce its costs. 【Objective】This paper presents an optimization method to calculate the pipeline layout and pipe diameters for micro-irrigation network operated under self-regulated pressure. 【Method】The length and diameters of the pipes were used as decision variables; the allowable water head difference between the branch pipes and the lateral pipes, the working pressure, the pipe diameter, water flow rates were used as constraints. With minimizing the total costs of the network as objective, an optimization model was derived to design the two-way capillary, self-pressure micro-irrigation pipe network, as well as the one-way capillary, self-pressure micro-irrigation pipe network, respectively. We applied the method to an irrigation project in Xinjiang with the optimization solved by the shuffled frog-leaping algorithm. 【Result】The model was capable of optimizing the pipeline layout and pipe diameters simultaneously for the micro-irrigation pipe network operated under self-regulated pressure. Implementation of the optimal results could noticeably save costs by reducing the numbers of section-pipes and the diameter of part of the section-pipes while in the meantime increasing the length of each section-pipes and the branch-pipes. Overall, it reduced the total costs by 21.5% to 469 129.3 yuan, compared to the results calculated by traditional design method. 【Conclusion】The shuffled frog-leaping algorithm was stable, efficient and accurate, and the optimization results calculated by it from our proposed model could reduce costs significantly. The method has implications for designing micro-irrigation pipe networks operated by self-regulated pressure in areas with relatively flatten surface and sufficient water source.

Keywords

• self-pressure
• micro-irrigation pipe network
• pipeline layout
• pipe diameter
• optimization
• sfla